Signal converters



Feb. 11, 1964 s. KUCHINSKY ETAL 3,121,219

SIGNAL CONVERTERS Original Filed March 15, 1958 PULSE INVENTOR SAULKUCHZNSKY RUDOLPH A. COLA SAMUEL R. SHAW ATTORNEY United States Patent3,121,219 SEGNAL C(lNVERTEliS Saul Kuchinsky, Somerville, N..l., andRudolph A. Cola and Samuel R. Shaw, Philadelphia, 1%., assignors toBurroughs Corporation, Detroit, Mich, a corporation of Michigan 1Continuation of application Ser. No. 721,228, Mar. 13, 1958. Thisapplication Dec. 15, W61, Ser. No. 160,970 16 Claims. (Cl. 340-4547)This invention relates to improved electronic circuits for convertingelectrical signms in one code system to another code system andparticularly for decoding and translating binary-coded signals intoother code systems.

This is a continuation of application Serial No. 721,228, filed March13, 1958.

For purposes of economy and simplicity, it is customary to employ abinary system of operation for electronic counters or computers. Theoutput of such a system is, of course, in the binary code, and it isdesirable to be able to convert this type of output to a more readilyuseful system, for example, the octal or decimal system. Electronicsystems are known for converting binary-coded signals to the decimalsystem or to some other system. However, such electronic systemsgenerally employ a di ode matrix or other multi-element matrix, anarrangement which is undesirable because of its complexity andcostliness. Other decoding systems employ mechanical apparatus'whichinclude switches, relays, and the like,

and are generally undesirable because of their compara- Accordingly, oneobject of the invention is to provide an improved electronic circuit fortranslating electrical signals from one code system to another codesystem.

Another object of the invention is to provide an electronic circuit forconverting signals in the binary system to the decimal system and'toother systems.

Still another object of the invention is to provide an improvedelectronic signal conversion circuit which is capable of storing signalswhich result from the conversion operation, the circuit beingcomparatively simple, reliable, and inexpensive.

The present invention is particularly suited for translatingbinary-coded signals to other code systems and, in brief, comprises acircuit which employs a multi-position electron beam device in which anelectron beam may be formed and switched from position to position, fromeach of which an output signal may be derived. In general, the number ofpositions employed, at which an electron beam may be formed, determinesthe system into which the binary-coded signal is converted. For example,if the conversion is to a decimal system, ten positions are employed andif the conversion is to an octal system, eight positions are employed. Aplurality of signal input means, each adapted to carry one element orbit of a binary-coded signal or number, are coupled to themulti-position electron beam and are adapted to apply the bits thereto.The bits are adapted to be combined in any desired Way so that, for anyselected corn- 3 l 2 l ,2 l 9 Patented Feb. 1 l, lgd l signal from whichrepresents the decimal or other equivalent number of the binary number.

The current flow which results from the conversion operation of the beamdevice may be maintained or stored for as long as desired in theselected position of the multi-position device and may ultimately beemployed in many different types of utilization devices and circuits.For example, the various positions in the beam device may be coupled toa visual indicating tube or the like so that the decimal number or otherequivalent of the binary-coded signal may be read directly.

The invention is described in greater detail by reference to thedrawings wherein:

PEG. 1 is a perspective view of one type of electron discharge deviceuseful in practicing the invention; and

FIG. 2 is a schematic representation of the device of FIG. 1 and acircuit in which it may be used in practicing the invention.

The circuits described below are particularly suitable for use with amulti-position electron beam tube of the type shown in US. Patent No.2,721,955 to Fan et al. This type of tube is shown in FIG. 1 as tube 10and includes, briefly, an envelope 12 which contains a centrallongitudinally elongated cathode l4 and ten groups of electrodes spacedradially equidistantly from the cathode and surrounding the cathode.Each group of electrodes includes a generally U-shaped elongated spadeelectrode l6 and a target electrode 18 positioned so that each targetoccupies the space between adjacent spade electrodes. Each spadeelectrode serves to form and hold an electron beam on its correspondingtarget electrode. A generally rod-like switching electrode 20 is alsoincluded in each group of electrodes and is positioned between one edgeof each target electrode and the adjacent spade electrode. The switchingelectrodes are known as switching grids. An open-ended cylindricalpermanent magnet 21 is provided surrounding the tube envelope andcoaxial therewith. The magnet provides an axial magnetic field which isutilized in conjunction with electric fields within the tube to form andswitch an electron beam from the cathode to each of the groups ofelectrodes. The direction in which the beam switches is always the sameand is determined by the orientation of the electric and magneticfields.

Briefly, in operation of tube It), electrons emitted by the cathode areretained at the cathode if each of the spades, targets and switchinggrids carries its normal operating electrical potential. When a spade orswitching grid experiences a suitable lowering of its potential, anelectron beam is formed and directed to the corresponding targetelectrode. The electron beam may be switched from one target electrodeto the next by thusv suitably altering the electrical potentials of aspade or switching grid. Under normal operating conditions, wheneverelectrode voltages are such that a beam might be supported at severalpositions, the beam will switch to the most leading position and lock inat this position.

In the circuit of H6. 2, the tube id is arranged to convert a 1-2-4-8binary number or signal to a number in the decimal system. The circuitof FIG. 2 includes an OR or signal mixing gate 22 which comprises adiode 24 having an anode 26 and a cathode 28 and a diode 39 having ananode 23 and a cathode 34. The anodes of the diodes 24 and 30 areconnected together, with the junction point 36 between them beingconnected through a suitable resistor 38 to a positive supply voltage ofabout volts. The supply voltage is also connected through a resistor 40to the cathode 28 of the diode 24 and through another resistor 42 to thecathode 34 of the diode 3%.

In FIG. 2, the tube ltl is shown schematically in linear form and thegroups of electrodes of the tube, numbered .Volt supply.

, bus.

3 to 9 as shown, represent positions at which an electron beam may beformed and from which an output signal may be obtained. In the circuitof FIG. 2, the

cathode 14 is connected to ground through a suitable resistor 44bypassed b-y a capacitor 46. The cathode is also connected to a source 45 of positive clear" pulses of about 150 to 2100 volts which are used todrive the cathode to a positive potential and thus clear an electronbeam from anyone of the tube positions at which it might be formed.

The target electrodes 18 are connected in the circuit as, follows. Thetarget electrodes are connected through suitable load resistors 52' to acommon target bus 54 which is coupled to a positive voltage supply ofabout 3G0 volts. The targets 18 may be connected to'any suitableutilization device. For example, each target may have an output terminal56 which is connected to one of the indicator cathode elements 58 of anindicator glow tubesuch as the type 6844 gaseousindicator tube. In suchan arrangement, the target at the 0 position is connected to the cathodenumeral zero; the targetat the 1 position .is connected to the cathodenumeral one, and so forth, as shown. To simplify the drawing, the otherelectrodes of such an indicator tube are not shown.

The spade electrodes in are connected in the circuit as follows. All ofthe spade electrodes are coupled through spade load resistor esto a.spade bus e2. which is coupled through a common spade resistor 64 to thepositive 150 A resistor as and a capacitor 6%; in parallel are providedbetween the ll spade resistor and the spade A similar parallel circuitincluding a resistor 65 and capacitor s7 is connected between the spadeload resistor of the 8 position spade and the spade bus d2.

Both parallel circuits are used in clearing and resetting a beam in thetube.

in addition, selected ones of the spade electrodes are connected asfollows. The point at which the O spade ,rcsistorozisconnected to theparallel combination of resistor 66' and capacitor as is coupled throughlead 79 to a switch 72 and from switch 72 through a lead 74 -t0 thecathode 14- of the tube itl. The 2 space is connected to the anode '76of a diode '73, the cathode Silt of which is connected through aresistordz to the cathode 34 r of the diode 3% The 4 spade is coupled bya lead 34 .resistor and the parallel combination of resistor 65 andcapacitor s7 is connected through a switch 95 to the cathode 14. I

Referring to the OR gate 22, the cathode 28 of the diode 24 is coupledto a switch as and from the switch by a lead 98 both to ground andthrough a switch 1% and a lead 1% to thecathode 34 of the diode Stl.

The switching grids Eli are connected inthe circuit as follows. Each ofthe-even-numbered switching grids, except the switching grid at the 4position, is connected to a common lead lob-which is coupled in turn tothe cathode 28 of the diode 24. The switching grid at the 4 position iscoupled by a lead Illtl'to the junction point 325 of the anodes-of thediodes 24 and 3%. The odd-numbered switching grids are connected to acommon lead 112 which is connected in turn by a lead 113 to the cathode34 of the diode Eatl.

The switches '72, 96, Hill, as, and 95 are connected to perform thefollowing operations. The switch 72 is employed in a Zero-set circuitwhich operates in conjunction with the clear pulse source 48 to clear anelectron beam from a position in the tube and to reset it at the fOposition. The switch is in a circuit which transmits the "1-bit orelement of the binary number to the tube it}; the switch 1% is in acircuit which transmits the 2-bit of the binary number to the tube it;the switch 86 is in a circuit which transmits the 4-bit of the binary 4number to The tube it); and tne switch is in a circuit which transmitsthe 8-bit 9f the binary number to the tube Ml.

To clarify the above-mentioned circuits, they are described separatelyas follows. The zero-set circuit extends from the volt supply throughthe common spade resistor 64, through the spade bus as, resistor 66 andlead 70 through the switch '72, and through the lead '74 to the cathodeand then to ground. The 1-bit circuit extends from ground through thelead 9'3 and the switch 96, through the diode 24 of the OR gate 22, andthrough the resistor 3b to the l5!) volt power supply. The 2-bit circuitextends from ground through the lead and the switch fitlil and lead M2through the diode and the resistor 38 of the OR gate to the .150 voltpower supply. "the 4-bit cir uit extends from ground through the cathoderesistor 44 through the lead '74 and switch do and lead to the 4 spadeand thus to the 150' volt power supply. The 8-bit circuit extends fromground through the cathode resistor 44 through switch 95 and throughresistors 65 and 64 to the 150 volt power supply.

In operation of the circuit of FIG. 2, before binary bits are applied tothe tube to effect a translating operation, a clear pulse is applied tothe cathode 14 from the no binary bits applied to the tube, and with theswitches 6, iii-ll, 86, and 95 open, a decimal zero reading is obtained.In order to obtain a decimal 1 count, the switch as is closed. Thisoperation connects the evennumbered switching grids 2% to ground and theelectron beam switches from the 0 position to the 1 position and thenumeral 1 is energized in the indicator tube. A decimal "2 count isobtained by closing switch 1%. This connects the 2 spade to groundthrough the resistor $2 and diode 78, and, at the same time, theoddnumbered switching grids and the 4 position switching grid are alsoconnected to ground through the lead. The'connection oi the 2 spade toground switchesan electron beam from the 0 spade to the 2 sp-ade.However, the connection of the odd-numbered grids and the 4 positiongrid to ground has no eliect on the beam. Thus, the beam remains in the2 position and the numeral 2 is energized in the indicator tube.

The decimal 3 count is obtained by closing switch 1%, opening switchldll, and then closing switch 96. As

described above, closing switch res forms an electron beam at the 2position, and, since switch 95 connects the even-numbered switchingelectrodes to ground, the electron beam is switched from the 2 positionto 3 position. A decimal 4 count is obtained by clo ring the switch 36and connecting the 4 spade to oath-- ode. This connection causes anelectron beam to switch to the 4 position. A decimal 5 representation isobtained by closing switch as, opening switch dtgand then closing switchas. This operation forms a beam in the: 4 position, and then thegrounded even-numbered switching electrodes switch the beam one moreposition to r the 5 position.

A decimal 6 representation is obtained by closing, switch 86, openingswitch $6, and then closing switch ltltl Switch dd causes a beam to formin the 4 position, and switch connects the odd-numbered grids to ground.

Since the grid at the 4 position is connected to the oddtion. This locksthe beam in securely at the 6 position and prevents any tendency of thebeam to switch ahead to the 2 position when the 2 spade is grounded byswitch 100.

A decimal 7 count is obtained by closing switch 86, opening switch 86,closing and opening switch lltlh and closing switch 96. -As describedabove, the closing and opening in turn of switches 86 and 1% causes abeam to form in the 6 position, and, since switch 96 controls theoperation of the even-numbered grids, the beam is switched one moreposition to the 7 position. A decimal 8 count is obtained by firstclearing the tube with a clear pulse from the source 48 and then withoutzero-setting, by closing switch 95 and connecting the 8 spade tocathode, whereby an electron beam forms in the 8 position. It isnecessary to clear the tube and then not Zero-set because a beam wouldnot switch from O to 8 since 8 is not a leading position with respect toO. A decimal 9 count is obtained by forming the beam at the 8 positionas described above and, in addition, closing switch 96 which connectsthe even-numbered grids to ground and thus causes the beam to switch byone position to the 9 position.

.The foregoing description of the invention rel-ates to the conversionfrom the binary to decimal system. -I he principles of the invention mayalso be employed to convert from the binary to the octal system. inpracticing such a conversion, the switch 95 and all of the circuitryassociated with positions 8 and 9 are omitted. In this case, only eightpositions, that is positions to 7 in the tube 10, are employed.

In operation of the circuit of :FIG. 2, the switches 72, 96, 18d 86, and95 are operated separately and serially beginning with '72, theZero-set, and then with the other switches being operated in order sothat the binary bits are applied in 842l order, with each switch beingclosed and then opened before the next one is operated. It is clear thatsuitable negative pulses. may be used in place of the various switches.In addition, the various elements or bits of the binary number may beapplied, either by a manually operated system or by an automatic system.

The invention thus described provides a new and novel circuit fortranslating signals from one code system to another in simple fashionwith the circuit being capable of storing the translated signal andutilizing the translated signal in different output circuits.

What is claimed is:

1. A circuit for converting an electrical signal from one code system toanother code system including an electron discharge device,

-a plurality of groups of electrodes in said device, each of which isadapted to receive an electron beam and provide an output signaltherefrom,

a plurality of signal input means coupled to said device,

each providing a separate signal bit,

each signal input means being coupled to a specific group of electrodesto which it is adapted to apply its signal bit,

said signal input means being operable to apply said bits in differentcombinations to said device,

each combination of signal bits having a meaning in a first code systemand when applied to said device, each combination of signal bits causingan electron beam to form at a zero position and then switch to a singlespecific group of electrodes from which an output signal then flows,

said output signal from said specific group of electrodes having ameaning in a second code corresponding to the meaning of the inputsignal bits in the first code.

2. The circuit defined in claim 1 wherein in said device each group ofelectrodes includes means for storing the output signal at each positionin said device.

3. The circuit defined in claim 1 wherein each group ti of electrodesincludes switching means for switching an electron beam from one groupof electrodes to another and each of said signal input means is coupledto one of said switching means.

4. The circuit defined in claim 1 wherein said electron discharge devicecomprises a magnetron beam switching tube in which eadi group ofelectrodes includes a target electrode which receives an electron beamand provides an output signal therefrom, a spade electrode which formsan electron beam and holds it on its associated target electrode, and aswitching electrode for switching an electron beam from one group ofelectrodes to another.

5. A signal conversion circuit including a multi-position electron beamdevice,

a plurality of electron beam controlling electrodes at each position insaid device,

signal input means coupled to electrodes at different positions in saiddevice and adapted to form an electron beam and position said beam at asingle position determined by the signal elements in an input signalthereto, the elements in said input signal being adapted to be groupedin a plurality of different ways with each grouping having its ownrepresentation in a first code,

output means at each position in said device for providing an outputsignal therefrom,

, each output signal corresponding to one particular group of inputsignal elements and each having a representation in a second code.

6. The circuit defined in claim 5 and including means for applying saidinput signal elements serially to said groups of electrodes whereby anelectron beam is formed in an arbitrarily designated first position insaid device and is switched rapidly to a final position determined bythe particular group of input signal elements.

7. A binary decoder including an electron beam switching tube comprisingan evacuated envelope containing a central cathode and a plurality ofgroups of electrodes surrounding said cathode;

each of said groups of electrodes comprising a position to which anelectron beam may flow;

each group of electrodes including a target electrode which receives anelectron beam and produces a corresponding output signal, a spadeelectrode adapted to form and hold an electron beam on the targetelectrode, and a switching electrode for switching an electron beam fromone group of electrodes to another;

means providing crossed electric and magnetic fields in said tubewhereby an electron beam is adapted to be switched from one group ofelectrodes to the next in one direction;

a plurality of signal input sources coupled to selected groups ofelectrodes at different positions insaid tube, the signals from saidsources being adapted to be arranged in different combinations eachhaving a meaning in a first code;

gating means coupled to said sources for applying signals therefrom indifferent combinations to' the corresponding groups of electrodes towhich they are coupled,

said selected signals being adapted to cause an electron beam in saidtube to switch in said one direction from an initial position to asingle position determined by the combination of said selected signals,

there being a single position to which an electron beam is switched foreachcombination of said signals, the current flow from each singleposition having a representation in another code corresponding to therepresentation in the first code of the combination of signal elementswhich caused the electron beam to switch to the single position.

8. The circuit defined in claim 7 wherein said signals are adapted to beapplied consecutively to the electrodes to which the signal sources arecoupled.

9. A signal converter circuit including an electron eam switching tubecomprising an evacuated envelope containing a central cathode and aplurality of groups of electrodes surrounding said cathode;

each of said groups of electrodes comprising a position to which anelectron beam may flow;

each group of electrodes including a target electrode which receives anelectron beam and produces a corresponding output signal, a spadeelectrode adapted to form and hold an electron beam on the targetelectrode, and a switching electrode for switching an electron beam fromone group of electrodes to another; means providing crossed electric andmagnetic fields in said tube whereby an electron beam is adapted to beswitchedfrom one. group of electrodes to the next in one direction;

signal input coupling means connected to selected .groups of electrodesat different positions in said tube and adapted to apply signals fromseparate signal sources in different combinations to the correspondinggroups of electrodes to which they are coupled;

said selected signals being adapted to cause an electron beam in saidtube to switch in said one direction from an initial position to asingle position determined by the combination of said selected signals,there being a single position to which an electron beam is switched foreach combination of said signals, the current flow from each singleposition having a representation in another code corresponding to therepresentation in the first code of the combination of signal elementswhich caused the electron beam to switch to the single position.

1 0. The circuit defined in claim 9 wherein said signal input couplingmeans are connected to selected spade electrodes and switching gridelectrodes.

11. A binary decoder comprising a multi-position electron tube includinga cathode and a plurality of groups of electrodes;

each of saidgroups of electrodes comprising a position at which anelectron beam may form;

each of said groups including a target electrode adapted to receive anelectron beam and provide an output signal therefrom, a spade electrodeadapted to form and -holdan electron beam on its associated targetelectrode, and a switching electrode adapted for switching anelectronbeam from one group of electrodes to the next;

means'in operative relation with said tube providing'crossed electricand magnetic fields therein by means of which an electron beam may beswitched from one group of electrodes to the next in one direction;

means providing a multi-bit binary signal;

means coupling one bit of said signal to selected ones of said switchingelectrodes;

means coupling another hit of said signal to others of i said switchingelectrodes;

-means coupling still another bit to one of said spade electrodes;

said bits being adapted to be applied to said tube in d-iiferentcombinations; each of said combinations causing anelectron beam to formin a different electrode, and a switching electrode adapted forswitching an electron beam from one group of electrodes to the next;

alternate ones of said switching electrodes being connected togetherdirectly to form two sets of electrodes;

one of said switching electrodes being connected indirectly to one ofsaid sets;

means providing a multi-bit binary signal;

means coupling one bit of said signal to one set of said switching,electrodes;

means coupling another bit of said signal to the other set of saidswitching electrodes;

means coupling still another bit to one of said spade electrodes;

said bits being adapted to be applied to said tube in differentcombinations;

each of said combinations causing an electron beam to form in oneposition in said tube;

said position representing the decimal equivalent of the selectedcombination of binary bits.

13. A binary decoder comprising a multi-position electron tube includinga cathode and a plurality of groups of electrodes;

each of said groups comprising a position at which an electron beam mayform;

said positions being numbered arbitrarily Zero, one,

two, three, four, five, six 11";

each of said groups of electrodes including a target electrode adaptedto receive an electron beam and to provide an output signal therefrom, aspade electrode adapted to form and hold an electron beam on itsassociated target electrode, anda switching electrode adapted forswitching an electron beam from one group of electrodes to the next;

all of said switching electrodes but one being connected in two setswith alternate electrodes being connected in each set;

a diode signal mixing gate comprising two diodes havin g theiranodesconnected together;

the cathode of one diode being connected to one set of switchingelectrodes;

the cathode of the other diode being connected to the other set ofswitching electrodes;

said one of said switching electrodes beingconnected to the anodes ofsad diodes;

means for providing a binary word comprising a plurality of signal bits;

means coupling one of said bits through one portion of said diodemixinggate to one set ofswitching electrodes;

means coupling another of said bits through said gate to the other setof switching electrodes;

and means coupling others of said bitsto selected ones of said spadeelectrodes.

14. A binary decoder comprising a multi-position electron tube includinga cathode and a plurality of groups of electrodes;

veach of said groups comprisinga position at which an electron beam mayform;

said positions being numbered arbitrarily zero, one,

two, three, four, five, six n;

each of said groups including a target electrode adapted to receive anelectron beam and to provide an output signal therefrom, a spadeelectrode adapted to form and hold an electron beam on its associatedtarget electrode, and a switching electrode adapted for switching anelectron beam from one group of electrodes to the next;

the switching electrodes at the odd-numbered positions being connectedtogether in one set;

the switching electrodes at the even-numbered positions except the fourposition being connected together in a second set;

a diode signal mixing gate comprising two diodes having their anodesconnected together;

the cathode of one diode being connected to said one set of switchingelectrodes and the cathode of the said position representing the decimalequivalent of other diode being connected to said other set of theselected combination of binary bits.

switching electrodes; 15. The decoder defined in claim 14 wherein saidsethe switching electrode at the four position being conlecte d ones ofsaid spade electrodes are the spade elecnected to the anodes of saiddiodes; 5 trodes at the second and fourth positions. means providing amulti-bit binary signal; T 16. The decoder defined in claim 14 whereinsaid semeans coupling one bit of said signal to said one set lected onesof said spade electrodes are the spade elecof said switching electrodes;trodes at the second and fourth positions and including a mfiansCoupling another bit of Said Signal to Said other diode coupled betweensaid spade at said second position set of switching electrodes; 10 andsaid set of switching electrodes at said odd-numbered means couplingstill other bits to selected ones of said iti spade electrodes; saidbits being adapted to be applied to said electrodes References Cited inthe file of this patent in different combinations; UNITED STATES PATENTSeach of said combinations causing an electron beam to form in oneposition in said tube; 2,807,748 Lee Sept 1957

1. A CIRCUIT FOR CONVERTING AN ELECTRICAL SIGNAL FROM ONE CODE SYSTEM TOANOTHER CODE SYSTEM INCLUDING AN ELECTRON DISCHARGE DEVICE, A PLURALITYOF GROUPS OF ELECTRODES IN SAID DEVICE, EACH OF WHICH IS ADAPTED TORECEIVE AN ELECTRON BEAM AND PROVIDE AN OUTPUT SIGNAL THEREFROM, APLURALITY OF SIGNAL INPUT MEANS COUPLED TO SAID DEVICE, EACH PROVIDING ASEPARATE SIGNAL BIT, EACH SIGNAL INPUT MEANS BEING COUPLED TO A SPECIFICGROUP OF ELECTRODES TO WHICH IT IS ADAPTED TO APPLY ITS SIGNAL BIT, SAIDSIGNAL INPUT MEANS BEING OPERABLE TO APPLY SAID BITS IN DIFFERENTCOMBINATIONS TO SAID DEVICE, EACH COMBINATION OF SIGNAL BITS HAVING AMEANING IN A FIRST CODE SYSTEM AND WHEN APPLIED TO SAID DEVICE, EACHCOMBINATION OF SIGNAL BITS CAUSING AN ELECTRON BEAM TO FORM AT A ZEROPOSITION AND THEN SWITCH TO A SINGLE SPECIFIC GROUP OF ELECTRODES FROMWHICH AN OUTPUT SIGNAL THEN FLOWS, SAID OUTPUT SIGNAL FROM SAID SPECIFICGROUP OF ELECTRODES HAVING A MEANING IN A SECOND CODE CORRESPONDING TOTHE MEANING OF THE INPUT SIGNAL BITS IN THE FIRST CODE.